Diagnostic and therapeutic tests and interventions, including imaging studies, radiology tests, prescriptions and various other procedures, are a significant portion of health care expenditures. In an effort to improve the quality and cost effectiveness of medical care, increasing emphasis has been placed on reducing inappropriate utilization of tests and interventions. It is believed that the reduction of inappropriate tests and interventions also may improve the quality of care by sparing patients from unnecessary procedures which may delay time to reach a correct diagnosis or may subject the patient to unnecessary risks.
Several methods have been implemented to manage utilization of tests and interventions. These methods include education in the form of expert opinion, precertification for expensive tests, profiling of a physician's ordering behavior for comparison to standards and other colleagues' profiles, capitation of the number of tests or interventions, consultation services, and case-based reasoning systems.
In the "Clearing the Way for Physician's Use of Clinical Information Systems" by James G. Anderson, in Communications of the ACM, August 1997, Vol. 40, No. 8, pp. 83-90, it is noted that there are many barriers to direct physician use of clinical information systems. In particular systems that either seek to change the physician's behavior or interfere with traditional practice routines are often not adopted readily by physicians.
When a system is accepted by physicians, there is also the risk that the system may reinforce bad practices by being based on assumptions about appropriateness of various procedures. For example, in systems using case-based reasoning, a physician's experience is used as a knowledge base of cases. A test for a patient is selected according to the test used for patients having similar indications. In "Case-Based Reasoning and Imaging Procedure Selection" by Charles A. Kahn, Jr., in Investigative Radiology, Vol. 29, p. 643 (June 1994), it is noted that one potential disadvantage with case-based reasoning is that such a system tends to follow the practices of its teachers, even if those practices are not optimal or up-to-date according to established practiced guidelines.
Even the establishment of practice guidelines may be difficult because there is often disagreement among physicians as to the appropriateness of various procedures. See, for example, "Appropriateness of Imaging Procedure Requests: Do Radiologists Agree" by Charles E. Kahn, Jr., et al., in AJR, Vol. 169, p. 11, July 1997. This reference indicates the lack of knowledge about the relationship between appropriateness of a procedure and actual patient outcomes.